A prime example of a sky region that is particularly prone to these challenges is the \(\mathcal {O}\) (\(10^\circ \) ) region surrounding the Galactic center (GC). The Galaxy is mostly transparent to photons in this energy range except at the highest energies [1]}, [2]}, and the emission is therefore integrated over the entire diameter of the Galaxy, likely making it the most complex region of the sky. This includes the GC which houses the supermassive black hole SgrA\(^{\ast }\)  [3]} and has the highest star formation rate (SFR) in the Galaxy [4]}, both of which are expected to impact the gamma-ray emission. In particular, the population of CRs could differ from that in the rest of the galaxy (due to e.g. freshly injected CRs [5]}), their diffusion could be position dependent [6]} and strong Galactic winds could be present in this region [7]}. Due to the high SFR a large number of individually unresolved sources is also expected to be present in the region, with their cumulative emission overlapping and possibly mimicking other emission components. The base of the Fermi bubbles (FB), a large structure centered at the GC [8]}, [9]}, is also expected to contribute to the measured emission, though the bubbles are challenging to detect close to the Galactic plane. In addition, the GC is expected to be the brightest place of a signal of dark matter (DM) particle pair-annihilation, at the verge of the sensitivity of current telescopes for the WIMP DM models.
